Object detection system

Abstract

An object detection system includes: a transmission unit transmitting a transmission wave; a reception unit receiving a reception wave which is the transmission wave reflected and returned by an object; a signal processing unit configured to sample a processing target signal corresponding to the reception wave and acquire a difference signal based on a difference between the processing target signal for at least one sample and an average of values of the processing target signals for samples; a detection processing unit detecting, based on a value of the difference signal, a distance to the object a plurality of times with a lapse of time; and an identification processing unit identifying the object based on a transition, with the lapse of time, between the distance to the object and the value of the processing target signal at the detection timing at which the distance to the object is detected.

What is claimed is: 
     
         1 . An object detection system, comprising:
 a transmission unit configured to transmit a transmission wave;   a reception unit configured to receive a reception wave which is the transmission wave reflected and returned by an object;   a signal processing unit configured to sample a processing target signal corresponding to the reception wave and acquire a difference signal based on a difference between a value of the processing target signal for at least one sample corresponding to a reception wave received at a certain detection timing and an average value of values of the processing target signals for a plurality of samples corresponding to a reception wave received in at least one of a first period and a second period respectively existing before and after the detection timing and having a predetermined time length;   a detection processing unit configured to detect, based on a value of the difference signal, a distance to the object at the detection timing a plurality of times with a lapse of time; and   an identification processing unit configured to identify the object based on a transition, with the lapse of time, between the distance to the object and the value of the processing target signal at the detection timing at which the distance to the object is detected.   
     
     
         2 . The object detection system according to  claim 1 , wherein
 the identification processing unit is configured to identify the object depending on whether the transition shows a first tendency in which the value of the processing target signal increases as the distance to the object decreases to a predetermined distance or less or shows a second tendency in which the value of the processing target signal decreases as the distance to the object decreases to the predetermined distance or less.   
     
     
         3 . The object detection system according to  claim 2 , wherein
 the identification processing unit is configured to determine whether the transition shows the first tendency or the second tendency based on a comparison result between the transition and a predetermined threshold value related to a correspondence relationship between the distance to the object and the value of the processing target signal.   
     
     
         4 . The object detection system according to  claim 3 , wherein
 the identification processing unit is configured to determine whether the transition shows the first tendency or the second tendency based on a plurality of comparison results between the transition and the threshold value.   
     
     
         5 . The object detection system according to  claim 2 , wherein
 the transmission unit and the reception unit are mounted on a vehicle, and   the identification processing unit is configured to identify a height of the object in front of the vehicle in a traveling direction depending on whether the transition shows the first tendency or the second tendency.   
     
     
         6 . The object detection system according to  claim 2 , wherein
 the transmission unit and the reception unit are mounted on a vehicle, and   the identification processing unit is configured to identify a position of the object with respect to the vehicle in the traveling direction depending on whether the transition shows the first tendency or the second tendency.   
     
     
         7 . The object detection system according to  claim 1 , wherein
 the transmission unit and the reception unit are mounted on a vehicle, and   the object detection system further comprising:
 a travelling control processing unit configured to control a traveling state of the vehicle depending on an identification result of the identification processing unit.